title: Visualization and measurement of capillary-driven blood flow using spectral domain optical coherence tomography.
abstract: Capillary-driven flow (CD-flow) in microchannels plays an important role in many microfluidic devices. These devices, the most popular being those based in lateral flow, are becoming increasingly used in health care and diagnostic applications. CD-flow can passively pump biological fluids as blood, serum or plasma, in microchannels and it can enhance the wall mass transfer by exploiting the convective effects of the flow behind the meniscus. The flow behind the meniscus has not been experimentally identified up to now because of the lack of high-resolution, non-invasive, cross-sectional imaging means. In this study, spectral-domain Doppler optical coherence tomography is used to visualize and measure the flow behind the meniscus in CD-flows of water and blood. Microchannels of polydimethylsiloxane and glass with different cross-sections are considered. The predictions of the flow behind the meniscus of numerical simulations using the power-law model for non-Newtonian fluids are in reasonable agreement with the measurements using blood as working fluid. The extension of the Lucas-Washburn equation to non-Newtonian power-law fluids predicts well the velocity of the meniscus of the experiments using blood.
authors.affiliation: Department of Mechanical Engineering, University Rovira i Virgili, Av. Països Catalans, 26, 43007 Tarragona, Spain; Department of Chemical Engineering, University Rovira i Virgili, Av. Països Catalans, 26, 43007 Tarragona, Spain.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cito
authors.forename: Yeh-Chan
authors.initials: YC
authors.lastname: Ahn
authors.forename: Jordi
authors.initials: J
authors.lastname: Pallares
authors.forename: Rodrigo Martinez
authors.initials: RM
authors.lastname: Duarte
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Chen
authors.forename: Marc
authors.initials: M
authors.lastname: Madou
authors.forename: Ioanis
authors.initials: I
authors.lastname: Katakis
keywords: Blood flow; Capillary-driven flow; Microchannel; Non-Newtonian fluid; Optical coherence tomography